The History Of The Computer Networks

Published Date: 02 Nov 2017

This topic covers mainly advanced wireless technologies like WIFI, WIMAX, LTE, LTE adv. As we know these topics are not new but what does this topic will cover is improvement in these technologies in latest time.

WI-FI is as we know the LAN based technology which basically works on IEEE 802.11 standards. This topic will Initially covers the fundamental of Wi-Fi technology like frequency band, Interoperability, Wi-Fi generations 802.11a, 802.11b, 802.11g and the latest 802.11n and their modulation and collision detection techniques. And then it will mainly concentrate on latest Wi-Fi alliance vision Seamless connectivity. In addition to this it also cites on Voice over Wi-Fi, WLAN and Health, Security and Multimedia.

Wi-Max is basically MAN based technology that works on the IEEE 802.16 standards. As similar to Wi-Fi this also will initially cover the same Fundamentals, Wi-Max generations, modulation techniques (OFDM and OFDMA) and collision detection techniques. Firstly this topic will cite on the advanced IEEE 802.16m standard and MIMO technology in the Wi-Max standard. Secondly it will cover the VoIP over Wi-Max on Wi-Max industry and Wi-Max equipment.

And In Addition to above two topics it also covers the LTE and LTE advanced their uplink and downlink modulations techniques. Moreover it will also cover the the difference between LTE and WI-Max and also does covers the "LTE adv" technology.

Contents

References 43

Introduction

Wi-Fi

Firstly, Section 1.1 will cover basic introduction about Wi-Fi and Wi-Fi alliance.

Secondly, Section 1.2 will be covering Wi-Fi frequency bands, IEEE 802.11 standards, key feature of latest 802.11n standard, Comparison between standards and challenges in deployment of IEEE 802.11nstandard.

Moreover, Section 1.3 will cite on the Wi-Fi alliance brief history

In addition, Section 1.4 will cover the Wi-Fi alliance certification and its classification

Sections 1.5 will Wi-Fi CERTIFIED Miracast, its topologies, key benefits, connection setup and certification details

Section 1.6 will cover the Wi-Fi CERIFIED Passpoint and its key features.

Section 1.7 will cover Wi-Fi direct and its key features.

Section 1.8 will cover the VoIP over Wi-Fi.

Section 1.9 will summarize this chapter.

WiMAX

Subtopic 2.1 will cover the basic introduction to WiMAX

Moreover 2.2 will cover the WiMAX frequency bands and IEEE 802.16 standards and its classification.

Section 2.3 will mainly cite on the security related to WiMAX

Most importantly 2.4 Will cite on the latest standard IEEE 802.16m and it will cover the comparison with 802.16e, key features of the standard, Bandwidth and Bands and Frame structure.

Section 2.5 will cite on the VoIP over WiMAX.

And 2.6 and 2.7 will cover the WiMAX certifications and 802.6m summary respectively.

LTE

In LTE, section 3.1 will cover the introduction to the LTE.

Section 3.2 will cover the Key feature of LTE.

Section 3.3 will cover the most important topic LTE advanced.

Section 3.4 will concentrate on the comparison between WiMAX and LTE

Finally 3.5 will cite on the timeline for WiMAX and LTE to reach the IMT advanced requirement.

Wi-Fi

Introduction

Wi-Fi and Wi-Fi alliance

Wi-Fi is basically wireless technology which was designed to support a LAN based services. The Wi-Fi based devices needs to be certified by the Wi-Fi alliance which is non-profitable organization. Its main goal is to expand the use of the Wi-Fi products all around the world. Wi-Fi alliance has completed more than 15000 products certification till now.

This chapter will very first cites on the Wi-Fi frequency band, Wi-Fi IEEE 802.11 standards and Modulation techniques. Then afterwards it will concentrate on the Wi-Fi alliance brief history. Furthermore it will concentrate on the type of certifications programs available by the Wi-Fi alliance. But It will mainly concentrates on the following certification standards Wi-Fi CERTIFIED n, Wi-Fi Direct, Wi-Fi certified Passpoint and Wi-Fi certified Miracast. In addition to following topics it will also explain the VoIP over Wi-Fi. From the following topics listed above it will explain the Wi-Fi CERTIFIED n, Wi-Fi Direct, Wi-Fi certified Passpoint, Wi-Fi certified Miracast more thoroughly because they are latest technologies presented by the Wi-Fi alliance. These topics are covered more thoroughly to explain the concept of the seamless connectivity. [1][2]

Wi-Fi frequency bands and Wi-Fi standards

Wi-Fi Frequency bands

Wi-Fi based products works on the radio waves. In the same manner as TV, radio, microwave and GPS works. Each of the devices works in the specific range of the radio frequency band. Wi-Fi based products work in the 2.4GHz or 5GHz license free bands. As Wi-Fi products works in the license free band it is important for the Wi-Fi based products to pass interoperability test. Moreover they also need to be aware of avoiding interference from the non-Wi-Fi devices working on the same licensed free band like remote control based toys. [1]

Wi-Fi IEEE 802.11 standards

Wi-Fi is divided in the different standard by the IEEE. Wi-Fi standards are called IEEE 802.11 standards and different standards available in the IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n and IEEE 802.11ac. They all differ from each other based on the services they can provide, data rates capability (Single of dual band), modulation schemes, collision detection techniques etc. [2] [3]

Key features of the latest standard 802.11n [4]

MIMO (Multiple inputs multiple outputs): This technology uses multiple antennas at transmitter and receiver ends. As radio frequency transmits it reflects in the path because of the objects in the path, which intern cause, the multipath reflection phenomena. Using Multipath reflection concept MIMO uses the spatial multiplexing which transmits the different data streams over same frequency but over different spatial channels. This technique is really helpful for efficient bandwidth utilization.

Dual band operation: 802.11n standard can operate in both the frequency band 2.4GHz and 5GHz.

Frame aggregation: The 802.11 standard uses shared half duplex MAC layer. So increase in number of packets will increase the packet overheads and will decrease the data rate or will have improper bandwidth utilization. To overcome this problem 802.11n standard aggregates several packets into a single packet using two different techniques. This in turn will avoid overhead problem.

Channel bonding: 802.11n standard merges two 20MHz channels in to one 40MHz channel unlike 802.11a and 802.11g standards which uses the 20MHz channel to double the bandwidth and increase the maximum throughput.

Interoperability: Devices in this standard can also operate in the previous standards.

Comparison of the 802.11 standards

Standard

Frequency Band

(GHz)

Max. Data rate

(Mbps)

Modulation

Range

(Meters)

802.11a

5

54

OFDM

~100

802.11b

2.4

11

DSSS

~100

802.11g

2.4

54

DSSS or OFDM

~100

*802.11n draft 2.0

2.4 or 5

300

DSSS or OFDM

**~150

Table (802.11 standards comparison) [4]

*MIMO is assumed as 2X2 and channel bandwidth is 40MHz

**50% range improvement is assumed than the previous standards

Standard

Non Overlapping channels

Wi-Fi certified

Interference sources

802.11a

23

Yes

Cordless phones

802.11b

3

Yes

Bluetooth, microwaves, Baby monitors etc.

802.11g

3

Yes

Bluetooth, microwaves, Baby monitors etc.

802.11n

3(2.4GHz) and 23(5GHz)

Yes

(Draft 2.0)

Same as 802.11 and g for 2.4GHz and

Same as 802.11a for 5GHz band

Table (802.11 standards comparison) [4]

Challenges in deployment of 802.11n

Interoperability performance issue: 802.11n does support the previous versions devices and APs but in it 802.11n may not fully utilized because previous standards transmit at slower rates. So 802.11n Stations will have to wait until station based on previous standard complete the transmission. This will increase the air time of the transmission,

Multipath reflection issue: 802.11n works on the MIMO technology which works on the concept of spatial multiplexing which is cause of multipath reflections. But if in the environment where multipath reflection in an issue will reduce the 802.11n performance.

Ethernet up gradation issue: As 802.11n data rate is around 300Mbps unlike previous standard. So when this standard will forward traffic on the wire network then such networks will require the Giga bit Ethernet which was fast Ethernet for previous standard. So not only the wireless networks but wired network too will require the up gradation issue. [4]

Wi-Fi alliance brief history

The Wi-Fi Alliance is a global non-profit industry association of hundreds of leading companies devoted to seamless connectivity. With technology development, market building, and regulatory programs, the Wi-Fi Alliance has enabled widespread adoption of Wi-Fi worldwide.

Wi-Fi alliance launches many certification programs that is very useful for advancement and enhancement of LAN based wireless connectivity. Following Figure 2.1 sites on the brief history of the Wi-Fi alliance.

Vision:

Seamless connectivity

Wi-Fi Alliance Mission:

Provide a highly-effective collaboration forum

Grow the Wi-Fi industry

Lead industry growth with new technology specifications and programs

Support industry-agreed standards

Deliver great product connectivity through testing and certification

Figure 2. (Wi-Fi alliance brief History) [1]

Wi-Fi alliance certification programs

Classification of Wi-Fi Alliance Certification program

Figure 2. (Certification general classification) [1]

Figure 2.3 and Figure 2.4 will further classify the programs mentioned in the Figure 2.2.

Figure 2. (Core Program classification) [1]

In Wi-Fi Optional Programs But in this classification mainly concentrates on the Programs concerned with seamless connectivity, VoIP, Security and Multimedia. In the next section Program based on seamless connectivity and VoIP will be Expalined in more Details.

Figure 2. (Optional program classification) [1]

Wi-Fi CERIFIED Miracast (Seamless Connectivity)

What is Wi-Fi Certified Miracast?

It is interoperability test program which provides seamless connectivity to display graphs, Video and audio contents between Wi-Fi devices without any cables and networks. Such devices are called to be "Wi-Fi Certified Miracast supported" devices. It is based on Wi-Fi display specifications.

Types of Equipment

TVs, handsets, laptops, cameras, set-top box and projectors

Requirement

To use this feature of Wi-Fi alliance both the devices should support the Miracast feature.

Core technology support

Figure 2. (Core program support) [5]

Miracast topologies

Miracast supports four different kind of topologies

Direct source to display:

Source is connected to display without the presence of AP. There is no cable and networks connectivity.

Source with access to AP and direct connection to Display

Source can stream the content from APS to display.

Direct source to display, AP present but not Connected

AP may be aware of Wi-Fi Miracast devices but not connected to them

Source and display connected to each other and AP

Source may stream content from itself of AP

Figure 2. (Miracast topology) [5]

Key benefits

Content support:

It can support any kind of content that source device can display without restriction of file format.

Cost effective

It uses Wi-Fi functionality already designed into connected devices do not require additional technology.

Demand driven connectivity

Unlike Device to device connectivity source can choose the content that it would like to display by establishing connectivity by application or services.

Easy to use

Devise can share the content with other devises seamlessly, without complex procedures

Strong Wi-Fi foundation:

It supports the entire core Wi-Fi technologies.

Interoperability

It works with any devices regardless of vendor as long as both the devices support Miracast.

Traffic management

Use Optimal channel using Wi-Fi direct and TDLs mechanism, to avoid congestion with neighbor network

Network Security

Wi-Fi protected Access 2 Protects users privacy as it does in the Wi-Fi certified network. [5]

Miracast Format support and connection setup

A Miracast connection session starts from the request from the source or display devices.

Content must present in source, or streamed from APs or downloaded from network or created by source itself.

If content is available then source device identifies available display devices and their display capabilities and then user chooses the display devices according to his convenience.

Now source device establishes link with chosen display devices for transmission. After establishment of the connection source device encodes the content and transmits it on Wi-Fi interface. During the transmission source device considers capabilities of display device like display resolution, video and audio format support. Some of the support formats are listed in Figure 2.7 in next page. [5]

Figure 2. (Miracast support formats) [5]

Finally the display device receives the content, decodes it and then renders it. Figure 2.8 below explains the mechanism explained above better way.

Figure 2. (Miracast connection setup)

Wi-Fi Miracast certification

Wi-Fi does not give a separate certificate for the Miracast but it is listed in the optional feature in the Wi-Fi interoperability Certificate.

Figure 2. (Miracast certification) [5]

WI-Fi CERTIFIED Passpoint

What is Wi-Fi Certified Passpoint?

It is interoperability test program which verifies that Wi-Fi equipments and mobile devices from different vendors will work well together with specific feature set.

Types of Equipment

APs, smart phones, tablets, laptops [6]

Features of the Passpoint

Network discovery and selection

Client device will discover and automatically chose the network based on the user preference, network preferences and availability.

Seamless network access

Wi-Fi hotspot access for in-network APs will no longer requires an active selection or input from the subscriber. Devices will be granted access automatically based on the multiple credentials. Like SIM based authentication, user name and password combination and certificate credentials. Figure below contains EAPs for credentials.

Figure 2. (Authentication for credentials) [6]

Security

All passpoint are secure with Wi-Fi WAP2 – enterprise for authentication and connection

Immediate account provisioning

Standardize and seamless process for new user account establishment.

Enterprise grade requirement

Voice quality should be consistently good

Voice traffic should be given priority by APs over data traffic

Sufficient bandwidth should be available all the time for Voice calls,

Seamless transition across the Wi-Fi network means voice call should be maintained as the user moves across the area

Must support WPA2 Enterprise security

APs must support power save mechanisms [6]

Key features of Wi-Fi Certified Voice - Enterprise.

Wi-Fi Certified Voice – Enterprise certified APs gives priority to Voice packet over data packets

Real time performance parameters like Latency, jitter and packet loss has measured using this test for correct transmission of the Voice traffic even in the peak traffic

Seamless connectivity for the user from one AP to another

Multiple vendor support

WPA2 advanced security protection.[6]

Wi-Fi Certified Voice – Enterprise certificate

There is no private certificate for the Wi-Fi Certified Voice – Enterprise but it comes as an extra feature under interoperability certificate similar to Miracast. [6]

Wi-Fi Direct

What is Wi-Fi Direct?

It is the certification for the devices which support the new Wi-Fi technology which allows Wi-Fi devices to connect directly allows them to do simple things like printing, sharing, sync and display.

Types of Equipment

Mobile phones, cameras, printers, PCs, gaming devices etc [7]

Feature of the Wi-Fi Direct

Portability

Such a devices can connect any time any ware in any fashion (one to one or one to many).

Easy to use

It has the feature that allows user to identify the available devices and services before connection.

Secure setup

It has the Wi-Fi protected setup, makes it simple to create secure connection between devices.

Wi-Fi traditional strength

Throughput and range, work with multiple vendor Wi-Fi Certified devices, WAP2 security.

New capabilities

Devices can find each other, Devices can identify the functionality of other devices, and Devices can connect to each other while staying connected to each other. [7]

Voice over Wi-Fi

What is Wi-Fi Certified Voice - Enterprise?

It is interoperability test program which provides common performance requirements for enterprise grade Voice capable Wi-Fi equipment.

Core technology support [8]

Enterprise usage model

Wi-Fi technology can be used by Voice capable devices using three different possible models

Figure 2. (VoIP deployment) [8]

Multiple-Location Mobile Worker (Yellow)

Such workers generally use Wi-Fi/cellular dual mode smartphones. While in the companies Wi-Fi coverage they uses the companies Wi-Fi application for voice communication and while they are not in the Wi-Fi coverage area they uses their cellular network for voice communication.

Single Location Mobile worker (Green)

Nurses, teachers, hotel catering staff, manufacturing technician spends theie most of the time at companies work sites such employees are provided Wi-Fi handset optimized for voice application controlled by IT department.

Non-Mobile Employee (Blue)

For Example Customer care agent can take Voice call on the laptop they have been assigned for that day which contains Voice application in it. [8]

Enterprise grade requirement

Voice traffic should be given priority by APs over data traffic

Sufficient bandwidth should be available all the time for Voice calls,

Seamless transition across the Wi-Fi network means voice call should be maintained as the user moves across the area

Must support WPA2 Enterprise security

APs must support power save mechanisms

Voice quality should be consistently good. [8]

Key features of Wi-Fi Certified Voice - Enterprise.

Wi-Fi Certified Voice – Enterprise certified APs gives priority to Voice packet over data packets

Real time performance parameters like Latency, jitter and packet loss has measured using this test for correct transmission of the Voice traffic even in the peak traffic

Seamless connectivity for the user from one AP to another

Multiple vendor support

WPA2 advanced security protection. [8]

Wi-Fi Certified Voice – Enterprise certificate

There is no private certificate for the Wi-Fi Certified Voice – Enterprise but it comes as an extra feature under interoperability certificate similar to Miracast.

Figure 2. (VoIP certification) [8]

Summary

To summarize this chapter covers fundamentals of Wi-Fi in starting and then it covers the Classification of IEEE 802.11 Standards and their features. Furthermore it also dose covers the brief history and classifications of the Wi-Fi alliance and then it mainly concentrates on the a Wi-Fi Certified Miracast, its key features, topologies and connection mechanism. Moreover it also does cover the Wi-Fi Certified pass-point and its feature, Wi-Fi Direct and its feature and Wi-Fi Certified Voice – Enterprise, its Enterprise usage model, requirement and key features fulfilling those requirements.

WiMAX (Worldwide Interoperability for Microwave access)

Introduction

WiMAX is basically wireless designed for MAN services, which offers wireless broadband access technology with similar features as Wi-Fi but coverage and QoS of Cellular network. WiMAX can provide broadband wireless access till 50km for Fixed stations and around 5 – 15km to mobile stations unlike Wi-Fi which has the range around 30-100 meters. Furthermore in WiMAX, Wi-Fi data rates are easily supported but with less interference that is because it does support both licensed and unlicensed Frequency bands.

Firstly this chapter will explains the frequency band of the WiMAX and the details of the IEEE 802.16 WiMAX standards. WiMAX IEEE 802.16 standards will cover brief comparison between 802.16a, 802.16c, 802.16e and 802.16m standards.[10]

WiMAX frequency bands and 802.16 standards

WiMAX frequency bands

WiMAX is less susceptible to the interference because it supports both frequency bands,

Licensed Free

Licensed

Licensed Free Band

Such frequency band can be used by anyone without the permission of legal issues. As we have seen in the Wi-Fi (2.4GHz and 5GHz)

Licensed band

In each country there are portions of the frequency band available for the commercial purpose such bands are known as licensed bands.

In US 2.5GHz really famous licenses band because it can provide very efficient point to multipoint transmission. Such band is used for BRS and EBS. BRS (broadband radio services) is for the commercial purpose and EBS (Education Broadband Services) is for the Educational as well as for the religious organizations. The entire in Europe and Asian countries 3.5 GHz band is really famous for broadband wireless.

For Interference free environment Point to Point transmission is famous mechanism in this multiple frequency spectrum holder can use the licensed bands in the same area. In US such spectrums are 900 MHz, 2.0 GHz, 6 GHz, 11 GHz, 18 GHz, 23 GHz and 39 GHz. 18GHz is the choice of most of the organization for cost and capability issue.

802.16 standards

802.16 is the first standard that concentrates on the line of site (LOS) issues at the spectrum ranges from 10GHz to 66GHz.

Figure 3. (IEEE 802.16 classification) [12]

WiMAX and security

Figure 3. (WiMAX encryption and authentication) [11]

IEEE 802.16m

Introduction

As we know 802.16m standard is an advancement of the 802.16e standard which has fulfilled following requirements in order to achieve higher data rate.

Multicarrier structure

Extended MIMO

Super frame structure

Comparison with 802.16e nstandard

Following Figure will explain the Comparison between two standards. Major goal behind this standard is to achieve higher data rates, Enhanced FDD support. Though this standard is under development so it’s may be possible that changes will take place in future. So this topic will cover mostly about Physical and MAC layer description.

Figure 3. (802.16m and 802.16e comparison) [12]

802.16m Features

Backward Compatibility

Interworking

Flexible frame format, Co-located coexistence for time sharing and handover capabilities to interwork with other technologies

Cell range and coverage

Connectivity up to 100km

Mobility

Connectivity up to 350 km/h

Latency

UP (User plane) : 10ms

CP (Control plane) : 100ms

Max. data rate

DL – 300Mbps for 20MHz channel

UL – 135Mbps for 20MHz channel

VoIP capacity

Greater than 60 active user/MHz/Sector

Figure 3. (Reduced guard band) [12]Bandwidth and Bands

802.16m has the reduced guard band compare to 802.16e as mentioned in the Figure 3.4

802.16e supported 20MHz channel bandwidth but with channel aggregation 802.16m can support up to 100MHz by using multicarrier operation. As shown in the Figure 3.5

Figure 3. (Multicarrier operation) [12]

802.16m guard band can be additionally use for data transmission.as mentioned in the Figure

Figure 3. (Guard band used for data transmission) [12]

Frame structure:

Legacy support:

802.16m has three mode 802.16m modes, 802.16m legacy mode and 802.16m mixed mode. Out of these three modes in legacy and mixed mode 802.16m has the backward compatibility for the 802.16e.

In DL and UL 802.16e frames are transmitted first followed by the 802.16m frames.

Figure 3. (802.16e legacy support)

Super frame

802.16m has feature called super frame to transmit large data packets. One super frame contains 4 of 5ms frames. As show in the Figure

It divides control information into long term and short term control information.

Long term information like Used carriers from the BS can be transmitted one in super frame

While Short term control information like channel condition can be transmitted once in every 5ms frames.

C:\Users\Gotu\Desktop\123.jpg

Figure 3. (Super frame) [12]

VoIP over WiMAX

Introduction

VoIP over WiMAX is the transport of voice data using the IP protocol MAN networks using WiMAX technology. However due to limited RF capacity and other challenges it is still in the beginning stage. This topic will cover the possible deployment scenarios of VoIP over WiMAX network.

Deployment scenarios

Fixed user End user VoIP termination

Here VoIP platform is in the same premises as WiMAX provider network

Figure 3. (VoIP over WiMAX) [11]

Mobile user

VoIP platform is in the same premises as WiMAX provider network.

Figure 3. (VoIP over WiMAX) [11]

Fixed user

VoIP platform is in separate premises from WiMAX provider network.

Figure 3. (VoIP over WiMAX) [11]

Mobile user

VoIP platform is in separate premises from WiMAX provider network.

Figure 3. (VoIP over WiMAX) [11]

Roaming

While WiMAX user is raoming VoIP platform may be at visitor’s side or at Home network.

Figure 3. (VoIP over WiMAX) [11]

Figure 3. (VoIP over WiMAX) [11]

WiMAX certifications

WiMAX certification is managed by the certification lab of WiMAX forum. This requires the following department in order to certify the device.

CWG (Certification working group): Manages certification program within the WiMAX forum. CWG work closely with TWG (Technical working group), NWG (Network working group), SPWG (Service provider working group). These groups develop the specification required for the WiMAX certifications. this can better understood by folling figure.

WiMAX certification labs are in USA, Taiwan, Chiana and Korea.

WiMAX 2.0 (IEEE 802.16m summary)

Following table shows the summary of latest standard of the WiMAX

Frequency bands

Licensed band from 450MHz to 3800MHz

Duplex

TDD, FDD and H-FDD

Scalable channel bandwidth

5,7,8.75,10,20 and 40MHz

Multi-carrier support for contiguous or non-contiguous channel

100MHz with channel aggregation

Increased DL peak channel and user data rate

More than 1Gbps for low mobility

More than 100Mbps for high mobility

Peak DL spectral efficiency

8.0 bps/Hz with (2x2) MIMO

15.0 bps/Hz with (4x4) MIMO

Peak UL spectral efficiency

2.8 bps/Hz with (1x2) SIMO

6.75 bps/Hz with (2x4) MIMO

VoIP capacity (2X2 MIMO on DL and 1X2 SIMO on UL )

More than30 Concurrent sessions per MHz per sector for AMR 12.2 kbps speech codec

Latency

User Plane: < 10 ms UL or DL

Control Plane: Idle to Active <100 ms

Frame structure

Super Frame: 20 ms

Frame: 5 ms

Sub-Frame: 0.625 ms

Mobility support

Up to 500 km/hr

2X increase in average DL spectral efficiency with (2X2) MIMO

>2.6 bps/Hz

>0.26 bps/Hz per User

2X increase in average DL cell edge user throughput

>0.09 bps/Hz/User

2X increase in average UL spectral efficiency with (1X2) SIMO

>1.3 bps/Hz

>0.13 bps/Hz/User

2X increase in average UL cell edge user throughput

>0.05 bps/Hz/user

Advance antenna system

DL: (2x2), (2x4), (4x2), (4x4), (8x8)

UL: (1x2), (1x4), (2x4), (4x4)

Backward compatibility

Backwards compatible with WiMAX R1.0 and R1.5

Table (WiMAX standard IEEE 802.16m brief history) [13]

Summary

To summarize this chapter mainly concentrates on WiMAX technology and it also does cites on the IEEE 802.16 standards and them it mainly does concentrates on the WiMAX security, VoIP over WiMAX and 802.16m standard. In the last it briefly summarizes the advance 802.16 m standard.

LTE (Long term Evolution)

Introduction

LTE was basically initiated by 3GPP (3rd Generation Partnership Project) to improve mobile phone standard. Main goal of this technology is to achieve higher data rate, cost reduction, low complexity, high spectral efficiency and frequency flexibility. LTE was developed to achieve higher performance over HSPA.

Figure 4. (LTE release history) [16]

LTE was introduced in Rel-8 of 3GPP as we can see from the Figure. Moreover LTE was also introduce to compete against latest WiMAX technology standard 802.16e Which can provide data rate up to 75Mbps while HSPA technology present at that time could only provide 14.4Mbps data rate. LTE is supported by the new radio technologies like OFDMA, frequency domain scheduling and MIMO. Moreover in 3GPP rel-9 enhancement in LTE like closed subscriber group (CSG), self-organizing network (SON) and Multimedia broadcast and multicast services (MBMS) were introduced.

In 3GPP rel-10 to LTE-advance was introduced to keep up with rapidly growing traffic and to compete with WiMAX standard 802.16m. LTE-adv technology will contain the advancements like carrier aggregation, Enhanced antenna transmission for uplink and CoMP transmission and reception. LTE-adv would be able to provide the downlink bandwidth in Gbps and augmentation with present LTE services, in near future wireless broadband services will be available for the use.

Key feature of LTE

OFDMA (downlink) and SC-FDMA(uplink)

OFDMA (downlink)

C:\Users\Gotu\Desktop\665.png

Figure 4. (OFDMA) [16]

In OFDMA the orthogonal narrowband carrier of the available bandwidth can be used by multiple user unlike OFDM in which only single user can use single narrowband at a time.

Figure 4. (OFDMA multiple user support)

SC-FDMA (uplink)

C:\Users\Gotu\Desktop\123.jpg

Figure 4. (SC - FDMA) [16]

SC-FDMA is same as OFDMA but same data is being transmitted over whole frequency but for shorter period of time.

MIMO (Multiple input multiple output) antennas

CSG (Closed subscriber group)

It is limited user connectivity access to small cell. Only the user have access to the cell are allowed to connect to cell other users are not permitted to do this

SON (Self organizing network)

SON network follows the given task to organize the network automatically

Inventory

Software download

Cell ID assignment

Coverage and capacity optimization

Load balancing etc.

LTE advanced

In 3GPP Rel-10 LTE-Advance was introduced, this standard was basically enhancement of LTE to get the data rates in terms of Gbps in cost efficient way, It is also referred 4G standard because if fulfils the complete requirement set by ITU for IMT advanced.

Figure 4. (Carrier aggregation) [17]Backward compatibility with LTE

Carrier aggregation to increase transmission bandwidth. In LTE channel bandwidth was 20MHz but in LTE advanced that is 100MHz.

Enhanced multi antenna support in order to gain higher bit rate throughput.

In an ideal condition maximum DL bit rate will be 1Gbps using 8X8 spatial multiplexing and for UL it will be 500Mbps using 4X4 spatial multiplexing.

Relay node: Relaying by relay node in order to improve coverage and cell edge throughput.

Comparisons between LTE and WiMAX

WiMAX 1.5

LTE (Rel-8 and 9)

Duplex

FDD

FDD

Channel BW

2X20 MHz

2X20MHz

BS antenna

MIMO (2X2)

MIMO(2X2)

DL modulation

64 QAM

64 QAM

DL peak channel rate

144 Mbps

144.4 Mbps

MS antenna

SIMO(1X2)

SIMO(1X2)

UL modulation

16 QAM or 64 QAM

16 QAM or 64 QAM

UL peak channel rate

43.2Mbps or 72 Mbps

82.9Mbps or 138.2Mbps

Table (WiMAX and LTE comarison) [13]

Time line for WiMAX and 3GPP to meet the requirement the IMT-Advanced

Figure 4. (Timeline support) [13]

Summary

To conclude, this chapter specifically concentrates on LTE technology, its key feature, advantages and its comparison with 802.16e standard. Moreover it also does concentrates on LTE advanced and its key features and then finally it cites on the time line to meet IMT advanced requirement by advanced technology.

Conclusion

Finally this topic mainly covers three advance wireless technologies Wi-Fi, WiMAX and LTE.

Firstly in LTE, it provides understanding of the frequency bands, IEEE 802.11 standards and then it mainly concentrates on seamless connectivity based Wi-Fi alliance certificates and its security aspects and VoIP over Wi-Fi.

Secondly, it covers the WiMAX a MAN based wireless technology, initially it concentrates on frequency bands and IEEE 802.16 standards classification and then it mainly explains the 802.16e and 802.16m most advanced standards. And finally it concentrates on the VoIP over WiMax.

In last it explains LTE and LTE advanced standards, its comparison with 802.16 IEEE standards and their key features.